HISTORY TREND FOR CP650 HMI
Creating a history trend is a two-step process:
- first you create a trend buffer to collect data for specified tags at specific points in time,
- then you configure a history Trend widget to display the collected data in a graphical format.
As i can see from screen shot you have not buffer for the variable. check attachment for creating a trend buffer
Once you create this, it will show history.
At present instead of buffer a variable is attached and hence it will only show real time value. (as no buffer is available for history)